This invention relates to a storage structure for storing the used or spent heating elements of nuclear power plants, in particular heating elements that have been previously used and the radioactive emissions of which have been greatly reduced. The structure comprises a plurality of tubes which may be square or rectangular in cross-section and which may include one or a plurality of chambers for receiving the spent heating elements.
Speaking more specifically, this invention relates to an improvement of the storage structure according to the German "Offenlegungsschrift" No. 27 30 850. In order to absorb horizontal shocks, as may occur at earthquakes, or the like, the base plates of adjacent tubes are joined together to form a storage structure less susceptible to yield to accelerating forces. In such a storage structure the individual storage tubes must be secured to it after their insertion at any given time and detached from it at any given time after their insertion.
In cases where the storage tubes are permanently secured to a composite storage structure, the latter becomes so bulky that it can hardly be transported from one place to another. This calls for single smaller storage units, applicable to be connected to, and to form part of, a large composite storage structure after they have been lowered into it. This, however, also causes great difficulties, particularly if the screw connections between the individual storage tubes and the composite structure are insufficient, resulting in formation of kinks or bents in them at the occurrence of horizontal forces.
The primary object of this invention consists in providing improved storage means of the aforementioned character not subject to the aforementioned limitations and drawbacks.
A more specific object of this invention is to provide improved storage structures wherein the individual storage tubes are secured against the effects of horizontal forces, and the locking of the individual tubes to their support is effected exclusively by the weight of the tube when lowered, and the unlocking of the individual tubes is effected automatically when they are lifted out of the storage structure.
Other objects of this invention will become more apparent as this specification proceeds.